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为什么盖革计数器会发出咔哒声 – 译学馆
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为什么盖革计数器会发出咔哒声

Why Do Geiger Counters Make That Clicking Sound?

《科学秀》
Sci Show
提问为什么盖革计数器会发出咔哒声?
假如你正在游戏的荣耀中安稳地度过一天
Say you’ve settled in for a day of gaming glory,
你正忙着探测《辐射4》中放射性荒野
and you’re busy cruising the radioactive wasteland of Fallout 4,
突然你的扬声器发出了噼啪 咔哒的噪音
when suddenly your speakers start emitting crackling, clicking noises.
玩家们并不是唯一会听出这种声音的群体
Gamers aren’t the only ones who will recognize that sound:
这是盖格计数器探测辐射时的典型噪音
it’s the characteristic noise of a Geiger counter detecting radiation.
但它证明了
But it turns out
你事实上听到的是游离电子的声音
that what you’re really hearing is the sound of rogue electrons.
盖革计数器由汉斯·盖革于1908年发明
The Geiger counter was developed in 1908 by Hans Geiger
并在二十年后被盖革的学生瓦尔特·米勒优化了
and perfected 20 years later by his student Walther Müller.
因此这种辐射探测器
So the radiation detector inside it
非常出人意料地叫做
is called, surprise, surprise,
盖革-米勒或者G-M计数管
a Geiger-Müller or G-M tube.
计数管是由金属制成的
The tube is made of metal
因此它可以导电
so it conducts electricity,
并且它里面充满着一般情况下不发生反应的气体
and it’s filled with a gas that’s normally inert,
或惰性气体 例如氖气
or nonreactive, like neon.
一根有电源供电的长金属棒
A long metal rod runs through the middle,
穿过管的中间
with a power source charging it.
一切都是稳定的
Everything is stable,
因为在金属棒和管壁间的惰性气体
because the inert gas between the rod and the walls
至少目前为止是不导电的
doesn’t conduct electricity—at least not yet.
这就是辐射的来源
That’s where radiation comes in.
在最基本的层面上
At the most basic level,
辐射是能量在空间中移动和在物体间转移的形式
radiation is how energy travels through space and is transferred between things.
盖革计数器专用于测量电离辐射
Geiger counters specifically measure ionizing radiation:
电离辐射即有足够能量可以
radiation with enough energy to
将电子从原子中剥离
strip electrons from atoms,
留下带正电离子的辐射
leaving behind positively-charged ions.
这使它有足够能力去损伤DNA
That also makes it powerful enough to damage DNA,
这就是电离辐射对生物有威胁的原因
which is why ionizing radiation is dangerous for living things,
也是我们热衷于探测它的原因
and why we have a vested interest in detecting it.
当放射性原子衰变时
When a radioactive atom decays,
它以亚原子粒子的形式产生电离辐射
it produces ionizing radiation in the form of subatomic particles.
而这就是你想用盖革计数器检测的
And with a Geiger counter, that’s what you’re looking to detect.
当电离辐射穿过G-M计数管的气体时
When the ionizing radiation passes through the gas inside the G-M tube,
它会击穿气体原子内部的电子
it knocks electrons off the gas atoms inside.
新释放的电子
The newly-freed electrons
被中心带正电的金属棒吸引
are attracted to the positively-charged rod at the center,
所以电子们嗖地射向了金属棒
so they zoom towards it.
当电子这样做时 它们会击打到其他原子的电子
And as they do, they knock electrons off other atoms,
这被称做汤森雪崩
in what’s called a Townsend avalanche.
这一连串被电离的原子
This cascade of atoms being ionized
在管内产生了足够多的带电粒子
creates enough charged particles inside the tube
以此在金属棒与管壁间短暂地传导电子
to briefly conduct electricity between the rod and the walls,
因此产生了瞬间电流冲击
so there’s a momentary surge of current.
当计数管连接扬声器的时候
When the tube is connected to a speaker,
这种电流会使扬声器部件快速地跳动
that current causes a rapid, jerking movement of the speaker components
即发出噼啪声或爆裂的声音
which is that crackling or popping noise.
当电子移动到中央的时候
While the electrons move toward the middle,
阳离子气体向另一个方向移动
the positive gas ions head the other way.
当这些阳离子子气体击打管壁时
When they hit the walls of the tube,
它们获得恢复初始状态的金属的电子
they pick up an electron from the metal returning to their original state
并重新定位探测器
and resetting the detector.
同样的爆裂声也可能发生在
The same crackling can also happen
通过扬声器的电流突然变化的情况下
with any abrupt change in the current running through your speakers
比如你不小心用音频线缠住转椅时
like you accidently roll your gaming chair of your audio cables.
谢天谢地 尽管这种爆裂并不意味着你需要找到一个铅盾
Thankfully, though that type of crackling doesn’t mean you need to go find a lead shield
现在 调整导管的设计和内部的气体
Now, tweaks to the tube design and the gas inside
可以使不同的盖革计数器
can make different Geiger counters slightly
或多或少地对不同种类的电离辐射敏感
more or less sensitive to different kinds of ionizing radiation.
但是它们仅对探测低水平辐射有用
But they’re only really useful for detecting somewhat low levels of radiation.
这是因为在电子管复位之前没有检测到任何辐射
That’s because any radiation that hits before the tube finishes resetting isn’t detected,
所以实际上他们低估了其在高辐射区域的危险性
so they actually underestimate the danger in high radiation areas.
因此这也许是不言而喻的
So this probably goes without saying,
但当你听到盖革计数器发出的噼啪声时
But if you hear a Geiger counter crackling,
立刻离开
stay away!
除非你有一些变异的猎犬排骨
Unless you’ve got some mutant hound chops
或者提神饮料来冲掉你的辐射吸收剂量
or a refreshing beverage to flush your rads,
就是这样
That is.
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视频概述

当你沉浸于游戏的快乐时,音箱中偶然传来的咔哒声是否很扫兴?你知道它是如何产生的吗?观看本期视频找到答案。

听录译者

收集自网络

翻译译者

Husky

审核员

审核员_Y

视频来源

https://www.youtube.com/watch?v=qtvz8lH5zhk

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